Silo-filler's disease is an acute condition caused by NO2. [Sullivan, p. 818] This often fatal disease occurs when farmers enter a silo 1 to 10 days after fresh silage has been stored. Like phosgene and ozone, it is less soluble that other irritant inhalants and more likely to cause severe pulmonary edema without the signs of severe upper respiratory injury. (See Comments for phosgene.) [LaDou, p. 522-5] NO2 poisoning may also cause methemoglobinemia. [Ford, p. 685] Blasting and diesel powered machines generate NO2 at levels of 0.02-0.8 ppm during tunnel construction. " . . . cumulative exposure to nitrogen dioxide showed the strongest association with a decrease in FEV1 in both non-smokers, and ever smokers." Two studies of miners exposed to nitrogen dioxide at 0.02-0.1 ppm found no effect on lung function. [Reference #2] Heavier than air--accumulates in enclosed spaces; TLV Basis = lower respiratory tract irritant; [ACGIH] Nitrogen dioxide is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans.

It has been reported that 10 to 20 ppm has been mildly irritating [Patty 1963]. Exposure to 150 ppm or more (no time period given) has been reported to cause death from pulmonary edema [NRC 1979]. It has been predicted that 50% lethality would occur following exposure to 174 ppm for 1 hour [Book 1982].

Comments

Silo-filler's disease is an acute condition caused by NO2. [Sullivan, p. 818] This often fatal disease occurs when farmers enter a silo 1 to 10 days after fresh silage has been stored. Like phosgene and ozone, it is less soluble that other irritant inhalants and more likely to cause severe pulmonary edema without the signs of severe upper respiratory injury. (See Comments for phosgene.) [LaDou, p. 522-5] NO2 poisoning may also cause methemoglobinemia. [Ford, p. 685] Blasting and diesel powered machines generate NO2 at levels of 0.02-0.8 ppm during tunnel construction. " . . . cumulative exposure to nitrogen dioxide showed the strongest association with a decrease in FEV1 in both non-smokers, and ever smokers." Two studies of miners exposed to nitrogen dioxide at 0.02-0.1 ppm found no effect on lung function. [Reference #2] Heavier than air--accumulates in enclosed spaces; TLV Basis = lower respiratory tract irritant; [ACGIH] Nitrogen dioxide is fibrogenic to the lungs in the context of an acute inhalation exposure complicated by bronchiolitis obliterans.

Reference Link

Exposure Assessment

Skin Designation (ACGIH)

Insufficient data

TIH

Yes

PEL (OSHA)

Ceiling(OSHA) = 5 ppm

MAK

0.5 ppm

Excerpts from Documentation for IDLHs

It has been reported that 10 to 20 ppm has been mildly irritating [Patty 1963]. Exposure to 150 ppm or more (no time period given) has been reported to cause death from pulmonary edema [NRC 1979]. It has been predicted that 50% lethality would occur following exposure to 174 ppm for 1 hour [Book 1982].